Naturalized refers to the process by which an individual becomes a citizen of a country other than their birth country. In the context of the United States, it specifically pertains to non-citizens who go through legal procedures to become citizens.
Related terms
Citizenship: The status of being a legally recognized member of a nation or country.
Immigration: The act of moving from one's home country to another with the intention of residing there permanently.
Emigration: The act of leaving one's home country to settle in another.